JPH0878003A - Nonaqueous secondary battery - Google Patents

Abstract

PURPOSE: To provide a nonaqueous secondary battery with high discharge voltage and long cycle life by using a specific compound as a positive electrode active material in the nonaqueous secondary battery comprising the positive electrode active material, a negative electrode active material, and a nonaqueous electrolyte. CONSTITUTION: In a nonaqueous secondary battery comprising a positive electrode active material, a negative electrode active material (example: Li-Al alloy), a nonaqueous electrolyte preferably containing LiPF6 as a supporting salt in a solvent (example: a mixture of ethylene carbonate and diethyl carbonate), as the positive electrode active material, Lix Moy with opposite spinel structure (M is at least one transition metal, x is 0-1.2, y is 3.8-4.2) is used. Preferably, Lix NiVO4 , and/or Lix CoVO4 (x is 0.1-1.2) is/are contained in the positive electrode active material. Preferably, particle size of the positive electrode active material is 0.5-50μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous secondary battery having a high voltage and good cycleability.

[0002]

2. Description of the Related Art Positive transition metal oxides for non-aqueous secondary batteries
As a polar active material, Fe having a spinel structure containing no Li
₃O_Four, Li-free reverse spinel structure (JP-A-56-
82574), LiMn having a spinel structure containing Li₂O
_Four(JP-A-58-220362), Li₂MnO₃, Γ
-βMnO₂And LiMn₂O_FourComplex oxide of γ-βM
nO₂And Li₂MnO₃Composite oxide of LiCoO₂,
LiCo_0.5Ni_0.5O ₂, LiNiO₂, V₂O_Five,
Amorphous V₂O_Five, V₆O₁₃, LiV₃O₈, VO
₂(B), TiS₂, MoS₂, MoO₃, LiMo₂
O_FourAre well known. Also, Science 26
Volume 4 Pages 1115 to 1118 In 1994,
LiNiVO_FourCan become a high-potential positive electrode active material.
Shows.

[0003]

An object of the present invention is to obtain a non-aqueous secondary battery having high voltage and high cycleability.

[0004]

Above problems SUMMARY OF THE INVENTION The positive electrode active material, negative electrode active material, the nonaqueous secondary battery comprising a nonaqueous electrolyte, Li _x MO _y cathode active material has a inverse spinel structure
(M: at least one transition metal, x = 0.1 to 1.
2, y = 3.8 to 4.2), which can be achieved by a non-aqueous secondary battery.

The spinel structure referred to in the present invention is a cubic close-packed structure.
1/8 of the anion tetrahedral hole (A site)
And cations occupy 1/2 of the octahedral hole (B site)
Structure, and in the general formula, AB₂X_Four, Or
ABB'X_FourIt is represented by. Where A, B and B'are positive
ON, X represents an anion. For example, MgAl₂O _FourIs
Mg [Al₂] O_Four, LiMn₂O_FourIs Li [M
n³⁺Mn⁴⁺] O_FourCan be expressed as In addition, the invention
Inverse spinel structure means that the position of cation is the same as spinel structure.
Are reversed, and the general formula is B '[AB] X_Fourso
expressed. For example, LiNiVO_FourThen, V [LiN
i] O_Four, LiCoVO_FourThen, V [LiCo] O_Four,
LiMgVO_FourThen, V [LiMg] O_Four, LiZnN
bO_FourThen, Nb [LiZn] O_FourCan be expressed as this is,
Generally, it is distinguished from the spinel structure.

The transition metal referred to in the present invention has an atomic number of 21.
Sc of 30 to Zn of 39, Y of 39 to Cd of 48.
Thus, it means La from 57 to Hg of 80. In the present invention
Is a combination of transition metals so that the valence of the transition metal is 7.
Preferably. Among them, V, Co, F
It is preferable to include e, Mn, Zn, Ti, Nb, and Mo.
Good A combination of +2 and +5 is particularly preferable. In particular
Include V or Nb as +5 valent transition metal element
Is preferred. For example, V, Nb and Ni, Co, M
It is preferable to combine n, Zn or Fe.
Especially LiNiVO _FourOr LiCoVO_FourIs preferred
Yes.

As a method for synthesizing the oxide of the present invention, a method of mixing and calcining a lithium compound and a transition metal compound or a solution reaction can be used for synthesis, and the calcining method is particularly preferable. The firing temperature used in the present invention may be a temperature at which a part of the mixed compound used in the present invention is decomposed and melted, and is preferably 250 to 2000 ° C, particularly preferably 350 to 1500 ° C. Furthermore, 600-1
300 ° C is preferred. The firing gas atmosphere used in the present invention is not particularly limited, but in the positive electrode active material, it is in the air or in a gas having a large proportion of oxygen (for example, about 30% or more), and in the oxide negative electrode active material described later, it is in the air. Alternatively, a gas containing a small amount of oxygen (eg, about 10% or less) or an inert gas (nitrogen gas, argon gas) is preferable. The firing time may be until the firing reaction is completed, but for example, 1 to 120 hours are preferable, and 1 to 48 hours are particularly preferable. Further, for example, when a lithium compound, a vanadium compound, a nickel compound, or a cobalt compound is mixed and fired, LiVO ₃ or Li ₃ VO ₄ may be produced. As described above, a compound having a low activity as a negative electrode active material or a precursor thereof may be included in the synthesis process. Such a compound may be contained as it is or may be removed.

The oxide of the present invention is preferably synthesized by firing a mixture of a lithium compound and a transition metal compound described below. Examples of the lithium compound include oxygen compounds, oxyacid salts and halides. As the transition metal compound, a monovalent to hexavalent transition metal oxide, the same transition metal salt, or the same transition metal complex salt is used.

Preferred lithium compounds used in the present invention include lithium hydroxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium sulfite, lithium phosphate,
Lithium tetraborate, lithium chlorate, lithium perchlorate, lithium thiocyanate, lithium formate, lithium acetate, lithium oxalate, lithium citrate, lithium lactate,
Examples thereof include lithium tartrate, lithium pyruvate, lithium trifluoromethanesulfonate, lithium tetraborate, lithium hexafluorophosphate, lithium fluoride, lithium chloride, lithium bromide and lithium iodide.

Preferred transition metal compounds used in the present invention include TiO ₂ , lithium titanate, acetylacetonato titanyl, titanium tetrachloride, titanium tetraiodide, titanyl ammonium oxalate and VO _d (d = 2 to 2.5). d =
Compounds of 2.5 are vanadium pentoxide), lithium compounds of VO _d , vanadium hydroxide, ammonium metavanadate, ammonium orthovanadate, ammonium pyrovanadate, vanadium oxosulfate, vanadium oxytrichloride, vanadium tetrachloride, lithium chromate. , Ammonium chromate, cobalt chromate, chromium acetylacetonate, MnO ₂ , Mn ₂ O ₃ , manganese hydroxide, manganese carbonate, manganese nitrate, manganese sulfate, ammonium manganese sulfate, manganese sulfite, manganese phosphate, manganese borate, chloric acid Manganese, manganese perchlorate, manganese thiocyanate, manganese formate, manganese acetate, manganese oxalate, manganese citrate, manganese lactate,
Manganese tartrate, manganese stearate, manganese fluoride, manganese chloride, manganese bromide, manganese iodide, manganese acetylacetonate, iron oxide (2 or 3 valent), ferric tetroxide, iron hydroxide (2 or 3 valent) , Iron chloride (2, 3 valent),
Iron bromide (2,3 valence), iron iodide (2,3 valence), iron sulfate (2,3 valence), ammonium iron sulfate (2,3 valence), iron nitrate (2,3 valence) iron phosphate ( (2 or 3 valent), iron perchlorate, iron chlorate, iron acetate (2 or 3 valent), iron citrate (2 or 3 valent),
Ammonium iron citrate (2,3 valent), iron oxalate (2,3)
Valent), ammonium iron oxalate (2,3 valent)

CoO, Co ₂ O ₃ , Co ₃ O ₄ , LiC
oO ₂ , cobalt carbonate, basic cobalt carbonate, cobalt hydroxide, cobalt sulfate, cobalt nitrate, cobalt sulfite, cobalt perchlorate, cobalt thiocyanate, cobalt oxalate, cobalt acetate, cobalt fluoride, cobalt chloride,
Cobalt bromide, cobalt iodide, hexaammine cobalt complex salt (as salts, sulfuric acid, nitric acid, perchloric acid, thiocyanic acid, oxalic acid, acetic acid, fluorine, chlorine, bromine, iodine), nickel oxide, nickel hydroxide, nickel carbonate, Basic nickel carbonate, nickel sulfate, nickel nitrate, nickel fluoride, nickel chloride, nickel bromide, nickel iodide, nickel formate, nickel acetate, nickel acetylacetonate, copper oxide (divalent), copper hydroxide, Copper sulfate, copper nitrate, copper phosphate, copper fluoride, copper chloride, ammonium chloride copper, copper bromide, copper iodide, copper formate, copper acetate, copper oxalate, copper citrate, niobium oxychloride, niobium pentachloride, penta Niobium iodide, niobium monoxide, niobium dioxide, niobium trioxide, niobium pentoxide, niobium oxalate, niobium methoxide, niobium ethoxide, niobium propoxide, niobium oxide Kishido, lithium niobate,
MoO ₃ , MoO ₂ , LiMo ₂ O ₄ , molybdenum pentachloride, ammonium molybdate, lithium molybdate, ammonium molybdophosphate, molybdenum acetylacetonate, WO ₂ , WO ₃ , tungstic acid, ammonium tungstate, and ammonium tungstophosphate are available. can give.

Particularly preferred transition metal compounds used in the present invention are TiO ₂ , titanyl ammonium oxalate, VO _d (d = 2 to 2.5), lithium compounds of VO _d , ammonium metavanadate, MnO ₂ and Mn _2. O
₃ , manganese hydroxide, manganese carbonate, manganese nitrate, manganese manganese sulfate, manganese acetate, manganese oxalate, manganese citrate, iron oxide (2 and 3 valent), ferric oxide, iron hydroxide (2 and 3 valent), Iron acetate (2,3 valent), iron citrate (2,3 valent), ammonium iron citrate (2,3 valent)
Valence), iron oxalate (2,3 valency), ammonium iron oxalate (2,
Trivalent), CoO, Co ₂ O ₃ , Co ₃ O ₄ , LiCoO
₂ , cobalt carbonate, basic cobalt carbonate, cobalt hydroxide, cobalt oxalate, cobalt acetate, nickel oxide, nickel hydroxide, nickel carbonate, basic nickel carbonate, nickel sulfate, nickel nitrate, nickel acetate, copper oxide (1,
Divalent), copper hydroxide, copper acetate, copper citrate, MoO ₃ , M
Examples include oO ₂ , LiMo ₂ O ₄ , WO ₂ and WO ₃ .

Particularly preferred combinations of lithium compounds and transition metal compounds used in the present invention are lithium hydroxide, lithium carbonate and / or lithium acetate and VO.
_d (d = 2 to 2.5), VO _d lithium compound, ammonium metavanadate, MnO ₂ , Mn ₂ O ₃ , manganese hydroxide, manganese carbonate, manganese nitrate, iron oxide (2,3 valent), 43 Iron oxide, iron hydroxide (2,3 valent), iron acetate (2,3 valent), iron citrate (2,3 valent), ammonium iron citrate (2,3 valent), iron oxalate (2,3 valent) , Ammonium iron oxalate (2,3 valent), CoO, Co ₂ O ₃ , C
o ₃ O ₄ , LiCoO ₂ , cobalt carbonate, basic cobalt carbonate, cobalt hydroxide, cobalt sulfate, cobalt nitrate, nickel oxide, nickel hydroxide, nickel carbonate, basic nickel carbonate, nickel sulfate, nickel nitrate, nickel acetate, Examples include MoO ₃ , MoO ₂ , LiMo ₂ O ₄ , and / or WO ₃ .

In addition to lithium compounds and transition metal compounds,
In general, compounds that enhance ionic conductivity, such as Ca ²⁺ ,
(For example, calcium carbonate, calcium chloride, calcium oxide, calcium hydroxide, calcium sulfate, calcium nitrate, calcium acetate, calcium oxalate, calcium citrate, calcium phosphate) or an amorphous network containing P, B, Si Forming agent (eg P ₂ O ₅ , Li
₃ PO ₄ , H ₃ BO ₃ , B ₂ O ₃ , SiO ₂ etc.) and the mixture may be fired. In addition, alkali metal ions such as Na, K and Mg and / or Si, Sn, Al and G
It may be mixed with a compound containing a, Ge, Ce, In, Bi or the like (for example, each oxide, hydroxide, carbonate, nitrate, etc.) and baked. Among them, it is preferably baked mixed with calcium carbonate or P ₂ O _5. The addition amount is not particularly limited, but 0.2 to 20 mol%
Is preferred.

Examples of preferable positive electrode active materials usable in the present invention include transition metal oxides and transition metal sulfides. Among them, manganese dioxide, vanadium pentoxide, iron oxide, molybdenum oxide, molybdenum sulfide, cobalt oxide, iron sulfide, titanium sulfide and the like are preferable.

In addition to the above-mentioned positive electrode active material, lithium-containing transition metal oxides are mentioned as a preferable positive electrode active material usable in the present invention. Particularly preferably, Li _x M _y O _z
(Here, at least one selected from M = V, Mn, Fe, Co, and Ni is the main component), x = 0.8 to 1.1, y = 1
Alternatively, 2, z = 1.5 to 5) can be mentioned. In addition to these, an alkali metal other than lithium, an alkaline earth metal, a transition metal other than M above, or IIIB
~ Group V B (Al, Ga, In, Ge, Sn, Pb, S
b, Bi) and the like. Moreover, P, B, etc. may be included.

Further preferred Lithium which can be used in combination with the present invention
The lithium-containing metal oxide positive electrode active material may be Li_xCo
O₂, Li_xNiO₂, Li_xCo_aNi_1-aO₂, L
i_xCo _bV_1-bO_z, Li_xCo_bFe_1-bO_z, L
i_xMn₂O_Four,, Li_xMnO ₂, Li_xMn
₂O₃, Li_xMn_bCo_2-bO_z, Li_xMn_bNi
_2-bO_z, Li_xMn_bV_2-bO_z, Li_xMn_bFe
_1-bO_z(Where x = 0.8 to 1.1, a = 0.1
0.9, b = 0.8 to 0.98, z = 1.5 to 5)
You can

The most preferable lithium-containing transition metal oxide positive electrode active material usable in the present invention is Li _x CoO 2.
₂ , Li _x NiO ₂ , Li _x Co _a Ni _1-a O ₂ , Li
_x Mn ₂ O ₄ , Li _x Co _b V _1-b O _z (where x =
0.8-1.1, a = 0.1-0.9, b = 0.9-
0.98, z = 2.02 to 2.3).

The preferable negative electrode material used in the present invention is selected from light metals, light metal alloys, carbonaceous compounds, inorganic oxides, inorganic chalcogenides, metal complexes and organic polymer compounds. Particularly preferred is a material containing a carbonaceous compound, an inorganic oxide, and an organic polymer compound. These may be used alone or in combination. For example, combinations of light metals and carbonaceous compounds, light metals and inorganic oxides, light metals, carbonaceous compounds and inorganic oxides are also preferable.

The light metal is lithium, and the light metal alloy is lithium alloy (Al, Al-Mn, Al-Mg, A).
1-Sn, Al-In, Al-Cd) are preferable. The carbonaceous compound is preferably a carbonaceous compound capable of inserting and releasing lithium ions or lithium metal. The carbonaceous compound is selected from natural graphite, artificial graphite, vapor-grown carbon, calcined carbon of organic matter, and the like. The carbonaceous compound is
It is preferable that even a slight amount of graphite structure is included. For example, natural graphite, petroleum coke, pitch coke, coal,
Examples include cresol resin-fired carbon, furan resin-fired carbon, polyacrylonitrile fiber-fired carbon, vapor-grown graphite, vapor-grown carbon, and mesophase pitch-fired carbon.
In addition to carbon, the carbonaceous compound may contain a heterogeneous compound. For example, B, P, N, S, etc. are 0-10.
It may be included by weight%. Moreover, you may contain SiC and BC.

The inorganic oxide is selected from transition metal oxides and semi-gold group oxides. As transition metals, V, Ti, Fe,
It is selected from Mn, Co, Ni, and Zn alone or a combination thereof. For example, Fe ₂ O ₃ , Co ₂ O ₃ ,
VO ₂ (B), WO ₂ , WO ₃ , MoO ₂ , MoO ₃ , and lithium-containing transition metal oxides are preferred. Among them, Li _e M _f O _g (where M = V, Ti, Mn, F
e, Co, Ni, at least one selected from Zn),
e = 0.1-3, f = 1 or 2, g = 1-5.5)
Is preferred.

Among them, Li _p Co _q V _1-q O _r
(Where p = 0.1-2.5, b = 0-1, z = 1.3
To 4.5) are particularly preferable.

In addition, it is made of an element of Group III to Group V of the periodic table.
An oxide is chosen. For example, Al, Si, Sn, Ge,
Pb, Sb, Bi alone or in combination
An oxide consisting of For example, Al₂O₃, SiO
₂, GeO, GeO₂, SnO, SnO₂, SnSiO
₃, PbO, PbO₂, Pb₂O₃, Pb₂O_Four, Pb
₃O_Four, Sb₂O₃, Sb₂O_Four, Sb₂O_Five, Bi₂
O₃, Bi₂O_Four, Bi₂O_Five, Li₂SiO₃, Li
_FourSi₂O₇, Li₂Si₃O₇, Li₂Si ₂O_Five,
Li₈SiO₆, Li₆Si₂O₇, Li₂GeO₃,
Li_FourGeO_Four, Li₈GeO₆, Li₂SnO₃, L
i₈SnO₆, Li₂PbO₃, Li_FourPbO_Four, Li
BiO₂, Li₃BiO_Four, Li_FiveBiO_Five, LiSb
O_Four, Li_FourMgSn₂O₇, Li₂MgSn₂O_FiveWhat
Oxides containing throat and the like are preferable. Also inorganic chalcogenides
As the metal, a metal or a semimetal indicated by the above-mentioned inorganic oxides
Is selected from sulfides using. For example, TiS₂, Ge
S, GeS₂, SnS, SnS₂, PbS, PbS₂,
Sb₂S₃, Sb₂S_Five, SnSiS₃Sulfide including
The thing is preferable. Among them, SnO and SnO₂, G
eO, GeO₂, SnSiO₃, Li₂SnO₃including
Compounds are preferred. In addition, these periodic table III-V group
It is preferable to include an amorphous network former in the coral reef.
Good For example, include oxides of B, P, Si and V
Is preferred. For example, P₂O_Five, Li₃PO_Four, H
₃BO₃, B₂O₃, SiO₂, V₂O_FiveAnd add
It is preferable to synthesize by The above carbonaceous compounds and oxides
Negative electrode active material has high capacity, high discharge potential, high safety and high
It is preferable because it gives the effect of icicle.

The surface of the positive electrode active material or the negative electrode active material of the oxide used in the present invention can be coated with an oxide having a chemical formula different from that of the positive electrode active material or the negative electrode active material used. This surface oxide is preferably an oxide containing a compound that is soluble in both acidity and alkalinity. Further, a metal oxide having high electron conductivity is preferable. For example, PbO ₂ ,
Fe ₂ O ₃ , SnO ₂ , In ₂ O ₃ , ZnO, or the like, or an oxide thereof preferably contains a dopant (for example, a metal having a different valence in the oxide, a halogen element, or the like). Particularly preferably, SiO ₂ , SnO ₂ , F
e ₂ O ₃ , ZnO and PbO ₂ .

The amount of the surface-treated metal oxide is preferably 0.1 to 10% by weight based on the active material. Also, 0.
2-5% by weight is particularly preferred, and 0.3-3% by weight is most preferred.

In addition to the above, the surface of the positive electrode active material can be modified. For example, the surface of the metal oxide may be treated with an esterifying agent, a chelating agent, a conductive polymer or polyethylene oxide. Also, the surface of the negative electrode active material can be modified. For example, the treatment may be performed by providing an ion conductive polymer or polyacetylene layer.

The average particle size of the positive electrode active material and the negative electrode active material used in the present invention is not particularly limited, but is 0.5 to 50 μm.
m is preferred. Furthermore, 0.5-20 micrometers is preferable.
A known crusher or classifier can be used to obtain a predetermined particle size. Examples thereof include a mortar, a ball mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling airflow type jet mill and a sieve.

The chemical formula of the compound obtained by firing was calculated by an inductively coupled plasma (ICP) emission spectroscopy as a measuring method, and as a simple method from the weight difference between the powders before and after firing.

A conductive agent, a binder, a filler and the like can be added to the electrode mixture. The conductive agent may be any electron-conductive material that does not cause a chemical change in the constructed battery. Usually, natural graphite (scaly graphite, flake graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber and metal (copper, nickel, aluminum, silver, etc.) powder, metal Conductive material such as fiber or polyphenylene derivative 1
It can be included as a seed or a mixture thereof.
In particular, it is preferable to include graphite because the cycle property is improved. Further, it is particularly preferable to use graphite and acetylene black together. The amount added is not particularly limited, but is 1 to 50.
Weight% is preferable, and 1 to 30 weight% is particularly preferable. For carbon and graphite, 1 to 15% by weight is particularly preferable. Furthermore, 1 to less than 5 wt% is preferable. The weight ratio of graphite to carbon black is preferably graphite alone, 10/1 to 1/1. Particularly, 5/1 to 2/1 is preferable.

As the binder, one or a mixture of polysaccharides, thermoplastic resins and polymers having rubber elasticity can be used. Preferred examples are starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose,
Diacetyl cellulose, polyvinyl chloride, polyvinylpyrrolidone, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, polybutadiene, fluororubber and polyethylene oxide. Can be mentioned. When a compound containing a functional group that reacts with lithium, such as a polysaccharide, is used, it is preferable to add a compound such as an isocyanate group to deactivate the functional group. The amount of the binder added is not particularly limited, but is preferably 1 to 50% by weight, and particularly 2
-30% by weight is preferred. The distribution of the binder in the mixture may be uniform or non-uniform. As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. Generally, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. The amount of the filler added is not particularly limited, but is preferably 0 to 30% by weight.

The electrolyte is generally dissolved in the solvent and the solvent.
Lithium salt (anion and lithium cation) to be solved
It is composed of As the solvent, propylene carbonate
-, Ethylene carbonate, butylene carbonate,
Dimethyl carbonate, diethyl carbonate, γ-bu
Tyrolactone, methyl formate, methyl acetate, 1,2-dime
Toxyethane, tetrahydrofuran, 2-methyltetra
Hydrofuran, dimethyl sulfoxide, 1,3-diox
Solan, formamide, dimethylformamide, dioxy
Solan, acetonitrile, nitromethane, ethyl monog
Lime, phosphate triester, trimethoxymethane, di
Oxolane derivative, sulfolane, 3-methyl-2-oxy
Sazolidinone, propylene carbonate derivative, tetra
Hydrofuran derivative, ethyl ether, 1,3-propa
And aprotic organic solvents such as
It is possible to mix and use one or more of these.
It As the cation of the lithium salt that dissolves in these solvents
For example, ClO_Four ^-, BF_Four ^-, PF₆ ^-, CF
₃SO₃ ^-, CF₃CO₂ ^-, AsF₆ ^-, Sb
F₆ ^-, (CF₃SO₂)₂N^-, B_TenCl_Ten ^2-, (1,
2-dimethoxyethane)₂ClO_Four ^-, Lower aliphatic cal
Bonate ion, AlCl4^-, Cl^-, Br^-, I^-,
Anion of chloroborane compound, tetraphenylborate iodide
And one or more of these
Can be used. Above all, ethylene carbonate
Is preferably included. Also ethylene carbonate
In addition to, propylene carbonate, 1,2-dimethoxide
Sietane or diethyl carbonate was mixed appropriately
LiCF as electrolyte₃SO₃, LiClO_Four, LiBF_Four
And / or LiPF₆An electrolyte containing is preferred.
In those supporting salts, LiPF₆Especially to include
preferable.

The amount of these electrolytes to be added to the battery is not particularly limited, but a necessary amount can be used depending on the amount of the positive electrode active material or the negative electrode active material and the size of the battery. The volume ratio of the solvent is not particularly limited, but in the case of a mixed solution of ethylene capote and 1,2-dimethoxyethane and / or diethyl carbonate, 0.4 / 0.6 to 0.6 /
0.4 (mixing ratio when both 1,2-dimethoxyethane and diethyl carbonate are used is 0.4 / 0.6-0.
6 / 0.4) is preferred. When adding propylene carbonate, 1 to 20 volume% is preferable. The concentration of the supporting electrolyte is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution.

In addition to the electrolytic solution, the following solid electrolytes can be used together. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Li-nitrides, halides, oxyacid salts, and the like are well known as inorganic solid electrolytes. Among them, Li ₃ N, LiI, Li _{5
NI 2, Li 3 N-LiI} -LiOH, LiSiO 4,
_{LiSiO 4 -LiI-LiOH, xLi 3} PO 4 -
_{(1-x) Li 4 SiO} 4, Li 2 SiS 3, it is effective and phosphorus sulfide compounds.

In the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ionic dissociative group, a mixture of the polymer containing an ionic dissociative group and the above aprotic electrolyte solution. A polymer matrix material containing a phosphoric acid ester polymer and an aprotic polar solvent is effective. Furthermore, there is also a method of adding polyacrylonitrile to the electrolytic solution. Also known is a method of using an inorganic and organic solid electrolyte in combination.

As the separator, an insulating thin film having a large ion permeability and a predetermined mechanical strength is used. A sheet or non-woven fabric made of olefin polymer such as polypropylene or glass fiber or polyethylene is used because of its resistance to organic solvent and hydrophobicity. The pore size of the separator is in the range generally used for batteries. For example, 0.01 to 10 μ
m is used. The thickness of the separator is generally within the range for batteries. For example, 5 to 300 μm is used.

Further, other compounds may be added to the electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivative,
Sulfur, quinone imine dye, N-substituted oxazolidinone and N, N'-substituted imidazolidinone, ethylene glycol dialkyl ether, quaternary ammonium salt, polyethylene glycol, pyrrole, 2-methoxyethanol, A
lCl ₃ , a conductive polymer electrode active material monomer, triethylenephosphoramide, trialkylphosphine, morpholine, an aryl compound having a carbonyl group, 12-
Crown ethers such as Crown-4, hexamethylphosphoric triamide and 4-alkylmorpholine,
Examples include bicyclic tertiary amines, oils, quaternary phosphonium salts, and tertiary sulfonium salts.

Further, in order to make the electrolytic solution nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolytic solution. Further, the electrolytic solution may contain carbon dioxide gas in order to have suitability for high temperature storage.

The mixture of the positive electrode and the negative electrode may contain an electrolytic solution or an electrolyte. For example, a method is known in which the ion conductive polymer, nitromethane, and an electrolytic solution are contained.

The collector of the electrode active material may be any electron conductor as long as it does not chemically change in the constructed battery. For example, for the positive electrode, in addition to stainless steel, nickel, aluminum, titanium, calcined carbon, etc. as the material, carbon on the surface of aluminum or stainless steel,
Those treated with nickel, titanium or silver, and the negative electrode are made of stainless steel, nickel, copper, titanium,
In addition to aluminum and calcined carbon, copper, stainless steel whose surface is treated with carbon, nickel, titanium, or silver), an Al-Cd alloy, or the like is used. It is also used to oxidize the surface of these materials. The shape is
In addition to the foil, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a molded body of a fiber group and the like are used. The thickness is not particularly limited, but is 1 to 5
Those having a diameter of 00 μm are used.

The shape of the battery can be any of coins, buttons, sheets, cylinders, flats, corners and the like. When the shape of the battery is a coin or a button, the mixture of the positive electrode active material and the negative electrode active material is used by being compressed into a pellet shape. The thickness and diameter of the pellet are determined by the size of the battery. Further, when the shape of the battery is a sheet, a cylinder, or a corner, the mixture of the positive electrode active material and the negative electrode active material is applied (coated) on the current collector, dried and compressed, and is mainly used. As a coating method, a general method can be used.
Examples thereof include a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a curtain method, a gravure method, a bar method, a dip method and a squeeze method. The blade method, knife method and extrusion method are preferred. Application is 0.1-100
It is preferably carried out at a speed of m / min. At this time, a good surface condition of the coating layer can be obtained by selecting the above-mentioned coating method according to the solution physical properties and drying properties of the mixture. The coating may be performed one by one or simultaneously on both sides.
The thickness, length and width of the coating layer are determined by the size of the battery, but the thickness of the coating layer on one side is particularly preferably 1 to 2000 μm in the compressed state after drying.

As a method for drying or dehydrating the pellets or sheets, a generally adopted method can be used. In particular, it is preferable to use hot air, vacuum, infrared rays, far infrared rays, electron beams, and low humidity air alone or in combination. The temperature is preferably in the range of 80 to 350 ° C, particularly 10
The range of 0 to 250 ° C. is preferable. The water content of the whole battery is preferably 2000 ppm or less, and the content of each of the positive electrode mixture, the negative electrode mixture and the electrolyte is preferably 500 ppm or less from the viewpoint of cycleability. As a pellet or sheet pressing method, a generally adopted method can be used, but a die pressing method or a calendar pressing method is particularly preferable. The pressing pressure is not particularly limited, but is 0.2 to 3 t /
cm ² is preferred. The press speed of the calendar press method is
0.1 to 50 m / min is preferable. Press temperature is room temperature ~
200 ° C. is preferred.

The mixture sheet is rolled or folded and inserted into a can, the can and the sheet are electrically connected, an electrolytic solution is injected, and a sealing plate is used to form a battery can. At this time, the safety valve can be used as a sealing plate. Other than safety valve,
Various conventionally known safety elements may be provided. For example, a fuse, a bimetal, a PTC element or the like is used as the overcurrent prevention element. In addition to the safety valve, as a measure for increasing the internal pressure of the battery can, a method of making a cut in the battery can, a method of cracking a gasket, a method of cracking a sealing plate, or a method of cutting with a lead plate can be used. Further, the charger may be provided with a protection circuit incorporating measures against overcharge and overdischarge. Also, as a measure against overcharge,
It is possible to provide a method of interrupting the current by increasing the internal pressure of the battery. At this time, a compound for increasing the internal pressure can be included in the mixture or the electrolyte. An example of a compound that increases the internal pressure is Li ₂ CO ₃ . For the can and the lead plate, a metal or alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper and aluminum or alloys thereof are used. As a method for welding the cap, the can, the sheet, and the lead plate, a known method (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.

The application of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when it is installed in an electronic device, a color notebook computer, a black and white notebook computer, a pen input computer, a pocket (palmtop) computer, a notebook. Type word processor, pocket word processor, e-book player, mobile phone, cordless phone handset, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk, Electric shaver, electronic translator, car phone,
There are transceivers, power tools, electronic organizers, calculators, memory cards, tape recorders, radios, backup power supplies, memory cards, etc. Other consumer products such as automobiles, electric vehicles, motors, lighting equipment, toys,
Game equipment, road conditioners, irons, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.), etc. Furthermore, it can be used for various military purposes and for space. It can also be combined with a solar cell.

A preferred combination of the present invention is the above chemical material.
It is advisable to combine the preferred components and battery components.
However, especially as a positive electrode active material, Li_xCoVO_FourAh
Ruiha Li_xNiVO_Four(Where x = 0.2 to 1.2)
As a negative electrode active material, one type of compound selected from
Metal, lithium alloy (Li-Al), carbonaceous compound,
Oxide (LiCoVO_Four, SnO₂, SnO, Ge
O₂, GeO, SnSiO ₃), Sulfide (TiS₂, S
nS₂, SnS, GeS₂, GeS), etc.
It is preferable to use one kind of compound. Electrode active material
The mixture used together with at least the electron conductive agent
Carbon material including graphite and acetylene black
May be mixed. The binder is polyvinylidene fluoride,
Fluorine-containing thermoplastic compounds, such as
Tylene butadiene rubber, ethylene propylene terpolymer
Do not use elastomers such as
You can In addition, as the electrolyte, ethylene carbonate
In addition, a ring such as diethyl carbonate,
Acyclic carbonate or ester such as ethyl acetate
LiPF as a combination of compounds and a supporting electrolyte₆Including
Mi, further, LIBF_Four, LiCF₃SO₃Such as Richi
It is preferable to use a mixture of um salts. In addition,
Polypropylene or polyethylene as a vibrator
Are preferred alone or in combination. Battery form
Is a coin, button, cylinder, flat, or square
But it's okay.

[0045]

EXAMPLES The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to the examples as long as the gist of the invention is not exceeded. Example 1 to 10] LiNiVO ₄ of _{Synthesis: Li 2 CO 3, NiCO 3} ·
_{2Ni (OH) 2 · 4H 2} O, NH 4 VO 3 and 0.5:
0.33: 1 mol of each was mixed in a mortar and baked in a porcelain crucible in the air at 850 ° C. for 6 hours. The obtained powder was pulverized and classified by a swirling airflow type jet mill to obtain a powder having an average size of 5 μm. LiCoVO ₄ synthesis method: Li ₂ CO ₃ , CoCO ₃ ,
NH ₄ VO ₃ was mixed in a mortar by 0.5: 1: 1 mol, and baked in a porcelain crucible in air at 750 ° C. for 6 hours. The obtained powder is crushed with a swirling airflow type jet mill,
Classification was performed to obtain a powder having an average size of 3 μm. 92.5% by weight of these positive electrode active materials, 3.5% by weight of flake graphite as a conductive agent, 1% by weight of acetylene black, and 3% by weight of solid content of polyvinylidene fluoride water dispersion as a binder. A positive electrode pellet (13 mmΦ, 0.35 g) obtained by compression-molding the mixture mixed in the mixing ratio was put in a dry box (dew point -4).
It was thoroughly dehydrated with a far infrared heater in a dry air (0 to -70 ° C) and used as a positive electrode material. As the negative electrode active material,
Lithium-aluminum alloy (80:20 weight ratio, 15
(mmΦ, 0.6 mm thickness), 94% by weight of graphite, 3% by weight of acetylene black as a conductive agent, and 3% by weight of solid content of polyvinylidene fluoride water dispersion as a binder. Negative electrode pellets (13 mm
Φ, 0.060 g) was thoroughly dehydrated with a far infrared heater in the same dry box as above and used as a negative electrode material. In addition, LiCoVO ₄ , SnO, or SnS
with iO _3, these negative electrode active material 88 wt%, 6 wt% of flaky graphite as a conductive agent, acetylene black 3
% By weight, and a negative electrode pellet (13 mmΦ, 0.060 g) obtained by compression-molding a mixture obtained by mixing a polyvinylidene fluoride water dispersion as a binder at a mixing ratio of solid content of 3% by weight in the same dry box as above. It was thoroughly dehydrated with a far infrared heater and used as a negative electrode material.

As the current collector, an 80 μm thick SUS316 net was welded to a coin can for both the positive and negative electrode cans. 250 μl of 1 mol / l LiPF ₆ (2: 8 volume mixture of ethylene carbonate and diethyl carbonate) was used as an electrolyte, and a microporous polypropylene sheet and polypropylene non-woven fabric were used as a separator. Was used by impregnating a non-woven fabric.
Then, a coin type lithium battery as shown in FIG. 1 was produced in the same dry box as above. In FIG. 1, a negative electrode mixture pellet 2 is enclosed between the negative electrode sealing plate 1 and the separator 3, and a positive and negative electrode mixture pellet 4 is enclosed between the positive electrode case 6 having the current collector 5 and the separator 3. Between the outer edge of the negative electrode sealing plate 1 and the outer edge of the positive electrode case 6,
A gasket 7 is provided. This lithium battery was subjected to a charge / discharge test in a predetermined voltage range at a constant current density of 0.75 mA / cm ² . All tests started with charging. Discharge voltage at that time, discharge capacity, cycleability (1 ~
Table 1 shows the discharge capacity change rate for 10 cycles.

[0047]

[Table 1]

The abbreviations shown in Table 1 above are as follows. (A) positive electrode active material, (b) negative electrode active material, (c) charge / discharge voltage range, (d) average discharge voltage, (e) discharge capacity,
(F) Cycle property (capacity change rate of 1 cycle and 10 cycles = (discharge capacity of 1 cycle−discharge capacity of 10 cycles) / discharge capacity of 1 cycle)

[Comparative Examples 1 to 5] The results of the same examples as those of the examples are shown in Table 1 except that LiMn ₂ O ₄ having a spinel structure is used as the positive electrode active material. [Comparative Examples 6 to 7] LiNiV was used as the positive electrode active material.
O ₄ and LiCoVO ₄ were used, the pellets of the same mixture as in the example were used, the same lithium-aluminum alloy as in the example was used as the negative electrode active material, and propylene carbonate and 1,2-dimethoxyethane were mixed in equal volumes as the electrolytic solution. Then
The same battery as that of the example was prepared except that 1 mol / liter LiBF ₄ was used as the supporting salt, and the same test as that of the example was performed. The results are shown in Table 2.

[Comparative Examples 8 to 9] A battery was prepared by using the same mixture, lithium-aluminum alloy and electrolytic solution as in Example 1 except that the same positive electrode active material as that in Example and acetylene black alone was used as the conductive agent. The same test as the example was carried out.

[0051]

[Table 2]

[0052]

INDUSTRIAL APPLICABILITY In a non-aqueous secondary battery composed of a positive electrode active material, a negative electrode active material, and a non-aqueous electrolyte, by using a lithium-containing transition metal oxide having a reverse spinel structure as the positive electrode active material, a high discharge voltage and a good discharge voltage can be obtained. A non-aqueous secondary battery having a cycle property can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a coin battery used in an example.

[Explanation of symbols]

 1 Negative Electrode Sealing Plate 2 Negative Electrode Mixture Pellet 3 Separator 4 Positive Electrode Mixture Pellet 5 Current Collector 6 Positive Electrode Case 7 Gasket

Claims (5)

[Claims] 1. A non-aqueous secondary battery comprising a positive electrode active material, a negative electrode active material, and a non-aqueous electrolyte, wherein the positive electrode active material has a reverse spinel structure Li _x MO _y (M: at least one transition metal, x = 0.1-1.2, y = 3.8-4.2) 2. The non-aqueous electrolyte supporting salt is at least Li.
The non-aqueous secondary battery according to claim 1, comprising PF _6. 3. The non-aqueous liquid according to claim 1, wherein the positive electrode active material contains Li _x NiVO ₄ and / or Li _x CoVO ₄ (x = 0.1 to 1.2). Secondary battery 4. The positive electrode active material has a particle size of 0.5 to 5.
It is 0 micrometer, The non-aqueous secondary battery of Claim 1, 2 or 3 characterized by the above-mentioned. 5. The nonaqueous secondary battery according to claim 1, wherein the conductive agent of the positive electrode active material contains graphite.